92 SC400

It could be the loss of back pressure from the intake/exhaust combo. I've seen similar things happen when N/A cars used exhausts made for turbo cars, albeit none of the losses were that significant; the most loss I think I saw was like 4whp. The fact that you lost power is not that surprising but the amount of loss is IMO.

Lextasy89

I have this same setup.. and I sure as hell didnt lose power

i3urton

wow intake plus exhaust = low whp ....all i can say is wow

lobuxracer

iTrader: (2)

Loss of backpressure? You mean increased backpressure. Bigger tubes present MORE backpressure to the exhaust ports than do smaller ones. Atmospheric pressure is one of the enemies in the whole exhaust battle.

lobuxracer

iTrader: (2)

This is exactly true, but the problem is most people don't understand what makes the gases leave faster. They very often believe bigger tubes are "better" when they are not, then they attribute the power they lost from going to big tubes to "loss of backpressure" which is equally misguided.

I've posted a lot of information about this a number of times, but I see the problem differently than most forum users because I've done a lot of work with air molecules from high pressure to high vacuum. Much of understanding it is counterintuitive.

phatboyc

But the best times at the 1/4 mile is when the atmospheric pressure is higher not lower...

Gernby

iTrader: (1)

That's because the atmostpheric pressure is higher at the intake side, not because it is higher at the exhaust side.

phatboyc

Yes but lobuxracer said it was one of the enemies of the exhaust. If it has more positive result on the intake for our N/A cars then I say it's a friend not an enemy.

Gernby

iTrader: (1)

It's one of those good outweighing the bad type of things. Think about how much of a restriction a turbo is on the exhuast, yet we know that it is still beneficial since it has a much greater positive impact on the intake side that vastly overcomes the restriction that it adds.

KvnChu

iTrader: (5)

old thread i know, but waht is the final judgment call on the loss of power?

norcal_c

I have almost the same setup and I'm afraid that mine might also reflect your numbers. I'm gonna try to get my car dyno'd soon.